On Tue, 23 Dec 1997 00:25:09 +0000 Philip Martin
<philip@PHILMART.DEMON.CO.UK> writes:
>Taa for the replies to the MPLAB question. I also RTFM and found the
>way
>to alter the INTCON bit to force the interrupt.
>
>Next, Ohhh what a night:
>
>Take this snipet-
>        movf    rmax,w          ; load w with max time count
>        xorwf   r1,f
>        btfsc   _z              ; has the max time been reached
>
>What I want to do is compare the value in rmax (value increasing each
>interrupt) with a fixed value in r1, read in at the beginning of the
>program from some BCD switches.
>
>What I've realised is that the result of the XOR is then placed in r1,
>overwriting the original data. My thinking now is to first transfer
>the
>data from r1 to w and on to a temporary register and then test the
>match. This would however mean doing this every pass (and in quite a
>few
>locations).


        How about just setting the destination of the XOR to w instead of
file?  this destroys w, but leaves your memory fine.

>        movf    rmax,w          ; load w with max time count
>        xorwf   r1,0           ; Set Z if equal, destroys W,
maintains r1
>        btfsc   _z              ; has the max time been reached
>


Harold